Toshiba CLEAN DRIVE

Aurex (TOSHIBA) has developed some analogue technology in 80's. For power amplifier, they use "Clean Drive" for their product in higher end level, such like Aurex SC-A90F.

Some technical briefing of Clean Drive: 

A third wire needed---Clean Drive

The role of an audio amplifier is to faithfully amplify the incoming signal and feed the amplified signal into the loudspeakers.

 

Scheme of the Clean Drive from SC-A90F.

Left=to Speaker

Right=to Input Negative

Distortion is the amount by which the amplifier alters the incoming signal. The standard distortion value quoted for amplifiers ls measured when a non-inductive, purely ohmic resistance is connected as the load.

 

This value becomes one order of magnitude higher if distortion is measured at the speaker input terminals in an actual-use situation.

 

That means the amplifier is not doing its job of simply amplifying the signal without adding its own coloration.

 

The Clean Drive system was developed with the purpose of allowing the amplifier to do its job as nearly perfectly as possible.

Furthermore, clean drive not only assures faithful signal amplification. it also drives the speakers with that same unaltered signal.

 

As can be seen in the diagram, sensor cords are connected to each speaker's 1-1 terminal.

 

The Clean Drive system detects spurious signals generated by the speakers and feeds them back to the amplifier where they are cancelled out.

 

Since the amplifier is now free of this source of distortion, its full capabilities can be used to drive the speakers without adding anything spurious to the amplified signal. (Fig. 1)

The Benefits of Clean Drive

The Clean Drive system improves sound quality in the following ways:

1.   Harmonic distortion at the speaker terminal is less than 10%

2.    Intermodulation distortion is significantly reduced.

3.    Frequency response is virtually flat.

4.    Optimum performance can be obtained with no adjustments regardless of the type of speakers and speaker cords.

5.    The influence of speaker cords on sound quality is eliminated.

1. 偕波失真大約原先的十分之一。
2. IMD大幅下降。
3. 頻率響應十分平直。
4. 不論何種喇叭與線材，不需調整即可得到最佳的表現。
5. 喇叭線對於聲音的影響幾乎消除。